Hot dogs or franks, sausages, hamburgers, chicken patties, and other food products typically are prepared by a manufacturer on one piece of equipment, and then loaded into an indexing type packaging machine with a separate loading machine. The food products frequently are oriented and aligned by the loading machine in a side by side configuration. In the past, loading machines have included loading heads which load food articles, such as hot dogs, into packaging trays positioned beneath the loading head. The loading head can be configured to group food articles into sets and load multiple packages at one time, and can accommodate packages of varying size and arrangement.
The rate at which food products may be packaged has been increasing. It is desirable that the speed at which the food articles are loaded be substantially equal to the speed at which the food articles can be packaged. There has been difficulty in developing a loading head operable at loading speeds comparable to the rate at which the food articles are capable of being packaged, however.
A loading head may include a sweeper device rotating one revolution per product group, to extract a group or set having a predetermined number of individual products from the loading machine and place the group onto a transfer conveyor traveling at a constant rate. This process continues until a predetermined number of product groups have been accumulated under an overhead stripper device. The stripper device discharges the product groups with an intermittent motion into the packages. The stripper device transfers the grouped food products from beneath the transfer conveyor into cavities of the packaging machine. The food products preferably are positioned over the cavities prior to operation of the stripper device.
The current industry loading head is limited in the number of pieces per minute it can process, in part by the cycle time of the stripper device. The stripper device operates during a time when the sweeper device is not transferring food products onto the transfer conveyor. As the food product group count becomes smaller, or the number of product groups per index of the packaging machine increases, then the time available for the strip cycle is reduced.
Thus, there is a need in the art for a loading head that loads food products into an indexing type packaging machine at a stripper device rate that is independent of the sweeper device rate. There is also a need for a stripper device that operates at a rate that is independent of the rate at which food products are supplied to the loading head.
In addition, the driving mechanisms of the stripper device and the sweeper device are typically coordinated, so that the speed of the sweeper device is directly related to rate at which the food products are being stripped. If food products become jammed in the sweeper device or other parts of the loading head, the packaging machine must be slowed while the problem is resolved. Slowing the packaging machine results in decreasing the speed at which the food products are being stripped. The speed and force with which the food products are stripped is important. The optimal strip rate is attained when the loading head is run at fill speed. As the rate is changed, the strip characteristics are changed, sometimes causing malfunctions.
Thus, there is a need in the art for a stripping device on a loading head that may operate independently of the overall operation rate of the loading head.
The disclosed invention achieves these needs and others by providing a loading head that creates a variable accumulation between the sweeper device and the stripper device, thereby allowing the stripper device cycle time to be independent of the sweeper device cycle time. In addition, a dedicated drive is provided for operating the stripper device, so that an optimum strip rate may be attained, even when the speed of the loading head is reduced. In addition, the invention permits the exit side of the transfer conveyor to have a position of zero relative speed, while the input side has a non-zero speed in order to permit food products to be supplied at a constant rate.